Santa Fe County Commissioner Liz Stefonics (l.) holds hands with her wife Linda Siegle after they were married in Santa Fe, N.M., Aug. 23. In August, the Santa Fe County clerk began issuing marriage licenses to same sex couples. Now New Mexico’s highest court will decide whether to legalize gay marriage in all 33 counties statewide.

Although the DOMA decision did not address the more fundamental constitutional issue, gay rights advocates are seizing on language from the decision to lay the ground work for a series of constitutional showdowns in both federal and state courts across the country.

On Wednesday, that campaign arrives at the New Mexico Supreme Court, where the court’s five justices will be asked to determine whether the state constitution requires recognition of same-sex marriages statewide.

“The plaintiffs have asked us to apply fundamental principles of constitutional law,” Albuquerque lawyer Peter Kierst, working with the ACLU of New Mexico, told reporters in a briefing.

“When the state creates a benefit it must make the benefit available to all equally,” he said. “Similar people must be treated similarly.”

Last week, the New Jersey Supreme Court ruled that civil unions in that state violated equal treatment principles of the New Jersey constitution because same-sex couples in civil unions were not entitled to receive the same federal benefits available to opposite-sex married couples.

New Mexico exists in a kind of middle ground in the national debate over same-sex marriage.

Nonetheless, in recent months a handful of county clerks in New Mexico began issuing marriage licenses for same-sex couples. The issue went to court and at least four judges have sided with the clerks.

Other clerks have refused to issue marriage licenses to same-sex couples until the courts resolve the question.

That’s what the hearing on Wednesday will address.

Earlier decisions by state court judges upholding the issuing of marriage licenses to same-sex couples represents a “departure from every official interpretation of the statutes and constitution,” wrote Albuquerque lawyer Daniel Ivey-Soto in his brief to the court on behalf of the New Mexico Association of Counties and most of the state’s county clerks.

He said that two attorneys general had analyzed the issue and concluded that neither state law nor any constitutional mandate required recognition of same-sex marriages.

“No new statutes or constitutional provisions have passed since 2004 with regard to this issue,” Mr. Ivey-Soto wrote.

Mr. Kierst is focusing his case on broader principles.

“The denial to same-sex couples of marriage’s benefits and the dignity and respect of being treated as equal persons with regard to marriage is a grave injustice,” Kierst wrote in his brief.

He said that New Mexico’s Equal Rights Amendment prohibits not only gender discrimination but also discrimination based on sexual orientation.

He said same-sex couples are fully qualified to marry under New Mexico law. They are single. They are not related to one another. They are of age. And they are prepared to pay the fee.

“When a county clerk refuses to issue a marriage license to a fully qualified couple simply because they are of the same sex, that clerk is treating similarly situated people differently based solely on their sexual orientation,” Kierst said in his brief.

He told the justices in his brief that the confusion among county clerks had resulted in a “patchwork of inconsistent practices in which same-sex couples’ constitutional rights are respected in some counties and not in others.”

“This inconsistency,” he added, “is unjust, unfair to all concerned, and within the power of the Court to remedy.”

Evie Jilek is an Albuquerque lawyer who filed a brief in the case on behalf of state lawmakers opposed to recognition of same-sex marriage.

She argues that the Equal Rights Amendment in the state constitution bars gender discrimination but not discrimination related to sexual orientation.

She said that after passage of the amendment in 1972, lawmakers repealed and rewrote a number of laws to fully comply with the new mandate for gender equality.

Ms. Jilek said the repealing and rewriting did not include an effort to redefine marriage in New Mexico to include same-sex couples.

“The marriage statutes treat men and women equally: both may marry someone of the opposite sex; and neither may marry someone of the same sex,” she wrote in her brief.

“The marriage statutes thus do not violate the ERA.”

The two consolidated cases are Griego v. Oliver and New Mexico v. Malott (34,306). A court clerk has said the justices are not planning to rule from the bench. A decision could take several months.